Field of the Invention
The invention relates to a memory device which, for the purpose of serial data transfer of binary data, is connected between two or more subscribers of a data transmission system. The memory device has a multiplicity of memory objects, preferably of equal size, that are identifiable by their address. The data width in each memory object corresponds at least to a predetermined data width of a data object intended for data transfer. A plurality of memory objects form a FIFO (first-in, first-out) structure. The invention also relates to a method for operating the memory device.
Bus systems are being used increasingly frequently for networking of distributed communications systems, for the purpose of data communication between different communications stations. In such bus systems, which are used particularly advantageously in motor vehicle electronics, a communications station communicates via a data bus with at least one other communications station which is connected to the same data bus. The bus system, in which various communications stations communicate with one another via a data bus as the communications medium, can be implemented, for example, in a known manner as a Controller Area network (CAN bus system) which is described in detail, for example, in “CAN-Controller Area Network: Grundlagen und Praxis [Principles and Practice]”, Wolfhard Lawrenz (publisher), 2d ed., Hüthig-Verlag, 1997.
Various processors are used in a CAN bus system owing to the multiplicity of communications stations, which are called network nodes here. In each of the network nodes, the central processor unit (CPU) of the corresponding processor then communicates with the respective CAN controller which, for its part, is coupled to the data bus. Owing to the different computation load on the various network nodes, resulting from the different computation performances of the corresponding central processor units in the corresponding processors at these network nodes, and owing to the normally defined transmission rate of the data bus which is connected to the CAN controller, a situation often arises in which it is not possible for the respective network nodes to process in real time all the data to be transmitted via the data bus.
However, at present, the access events between the central processor unit and the CAN controller to data records can be decoupled only by joint software protocolling. However, this process is extremely complex and also requires the processors to have greater computation performance.